Vacuum assisted biopsy needle set

ABSTRACT

A biopsy device having a cutting element is disclosed. The cutting element includes an inner cannula having a tissue receiving aperture disposed proximate a distal end thereof and an inner lumen. The inner cannula is slidably disposed within the inner lumen of an outer cannula. A vacuum chamber is disposed about at least a portion of the cutting element and is configured to create a vacuum in the cutting element during a biopsy procedure. The inner cannula is advanced distally outwardly and to cause the vacuum to be generated in the vacuum chamber. The vacuum is delivered to the cutting element whereby tissue is drawn into the tissue receiving aperture. The outer cannula is advanced distally outwardly after the inner cannula such that tissue drawn into the tissue cutting aperture is severed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation-in-Part of U.S. Pat. application Ser.No. 10/964,959 filed Oct. 14, 2004 which claims priority to U.S.provisional patent application Ser. No. 60/510,866 filed on Oct. 14,2003, which both applications are incorporated herein by reference intheir entireties.

FIELD OF THE INVENTION

The present invention generally relates to the field of tissue samplingand harvesting. More specifically, the invention relates to biopsyneedle sets and devices.

BACKGROUND OF THE INVENTION

In the practice of diagnostic medicine, it is often necessary ordesirable to perform a biopsy, or to sample selected tissue from aliving patient for medical evaluation. Cytological and histologicalstudies of the biopsy sample can then be performed as an aid to thediagnosis and treatment of disease. Biopsies can be useful in diagnosingand treating various forms of cancer, as well as other diseases in whicha localized area of affected tissue can be identified.

Biopsies are routinely performed on tissue using a needle set, whichtypically includes a stylet with a pointed tip and a notch defined nearits distal end. The stylet is slidably disposed within a cannula so thatthe notch can be alternately exposed or covered. Typically, a hub isconnected to the proximal end of each needle. Such needle sets are usedwith or incorporated in various forms of biopsy devices, such as thesingle action and double action biopsy devices. One such needle set isincorporated into the single action biopsy device shown in FIGS. 1-4.

Referring to FIGS. 1-4, single action biopsy device 20 includes an outerhollow needle 22 defining a lumen 24 therethrough. A stylet 26 isslidingly disposed within lumen 24 and is moveable relative to outerneedle 22. A first or distal end 28 of stylet 26 is provided with atissue cutting-point 30 and a cavity 32 adjacent to first end 28 forreceiving tissue samples. Stylet 26 is slidable relative to outer needle22 between a first or retracted position (FIG. 3) and a second orextended position (FIG. 2).

In the first position, stylet 26 is retracted within lumen 24 so thatouter needle 22 covers cavity 32. In the second position, the first end28 of stylet 26 is extended away from outer needle 22 to expose cavity32 to tissues at the biopsy site.

During a biopsy procedure, device 20 will be positioned with the cavity32 at the targeted site for the biopsy. Stylet 26 is momentarily driveninto the tissue far enough to expose cavity 32. Tissue then prolapsesinto cavity 32. The device is then fired to advance outer needle 22along stylet 26 to cover cavity 32. This forward movement of outerneedle 22 severs the prolapsed tissue to obtain a tissue sample, whichbecomes trapped in cavity 32 of stylet 26. With outer needle 22 blockingthe opening of cavity 32, biopsy device 20 is then withdrawn from thetarget site, carrying the sample within cavity 32. To collect the biopsysample, outer needle 22 is once again retracted to expose cavity 32 ofstylet 26. The procedure may be repeated several times untilsatisfactory samples have been obtained.

The firing mechanism 40 for such known single action biopsy devices isshown in FIG. 4. Firing mechanism 40 includes a housing 27 having fingergrips 41 and 42. An actuator 43 is operatively engaged with both thestylet 26 and outer needle 22. Actuator 43 includes a gripping portion44 and a drive mechanism 45. Drive mechanism 45 operates to depress adrive carriage 46 against the action of a spring 35. Housing 27 includesa resilient latch 36 that engages an underside 47 of the carriage 46 inthe retracted position. Latch 36 is released by forward movement of thedrive mechanism 45 so that the spring 35 urges carriage 46 outwardly,which in turn thrusts outer needle 22 over the sampling cavity 32 of thestylet 26. Cover 49 snap-fits over housing 27 to protect spring 35 andthe sliding engagement between carriage 46 and housing 27 from debrisand interference.

Double action biopsy devices also employ similar needle sets. In adouble action biopsy device, movement of inner and outer needles 26, 22to capture a sample occurs almost instantaneously by means of a firingmechanism engaged with proximal ends 29 of needles 26, 22. A doubleaction biopsy device is disclosed in U.S. Pat. No. 5,538,010.

While these single and double action biopsy devices are widely used, abasic problem remains in the field of biopsy, which is the need toobtain a sufficient amount of sample tissue. One potential cause of theproblem is that as the outer needle passes over the tissue cavity, theouter needle has a tendency to push the tissue away from the cavity.This results in samples that are inferior in quality or too small, whichprecludes the pathologist from conclusively determining whether diseaseis present, and if so, to what extent it has progressed. The pathologistmust then issue an inconclusive diagnostic report. This causes thephysician to recall the patient and attempt another needle biopsy, or insome situations, the patient is scheduled for a more invasive, traumaticand expensive procedure such as an open surgical biopsy.

The challenge has been to consistently obtain sufficient tissue volumeand quality tissue cores, regardless of tissue type, to meet the needsof the pathologist so that a conclusive diagnosis can be achieved.Therefore, a need remains for advice that can consistently achieve thisresult.

SUMMARY

An embodiment of a biopsy device having a cutting element is disclosed.The cutting element includes an outer cannula having a tissue receivingaperture disposed proximate a distal end thereof and an inner lumen. Aninner cannula is slidably disposed within the inner lumen of the outercannula. The inner cannula also has an inner lumen and includes an opendistal end defined by a sharpened circumferential edge. A vacuum chamberis disposed about at least a portion of the cutting element and isconfigured to create a vacuum in the cutting element during a biopsyprocedure. The outer cannula is advanced distally outwardly to cause thevacuum to be generated in the vacuum chamber and delivered to thecutting element whereby tissue is drawn into the tissue receivingaperture. The inner cannula is then advanced distally outwardly afterthe outer cannula such that tissue drawn into the tissue cuttingaperture is severed.

In an alternative embodiment of the biopsy device, a trigger operates tofirst cause the inner cannula to be advanced distally outwardly and tocause a vacuum to be generated such that tissue is drawn into a tissuereceiving aperture formed in the inner cannula. Thereafter, the outercannula is advanced distally outwardly such that tissue drawn into thetissue receiving aperture is severed.

In at least one other embodiment of the biopsy device, a vacuum bed isformed at the distal end of the inner cannula for providing a uniformvacuum throughout the tissue receiving aperture. A trocar blank isinserted into the distal end of the inner cannula which is then groundor machined to form the vacuum bed. The vacuum bed includes at least onevacuum channel or aperture which operates to uniformly distributesvacuum air over the entire vacuum bed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side elevational view of a prior art biopsy device;

FIG. 2 is an enlarged fragmentary view of the device of FIG. 1, showingdetails of the tip of the device when in an extended position;

FIG. 3 is an enlarged fragmentary view of the device of FIG. 1 showingdetails of the tip of the device when in a retracted position;

FIG. 4 is an exploded view of the device of FIGS. 1-3.

FIG. 5 is a partial sectional view showing a needle set according to anembodiment of the present invention;

FIG. 6 is a side elevational view of an outer member of the needle setof FIG. 5;

FIG. 7 is a side elevational view of an inner member of the needle setof FIG. 5;

FIG. 8 is a partial side sectional view of the needle set in a retractedposition;

FIGS. 9A and 9B are partial side sectional views of the needle set ofFIG. 5 in an extended position;

FIG. 10 is an enlarged side elevational view of the distal end of theneedle set of FIG. 5;

FIG. 11 is a side sectional view of the distal end of another embodimentof a needle set;

FIG. 12 is a cross sectional view of the needle set of FIG. 11 takenalong line 12-12 of FIG. 11.

FIG. 13 is a cross sectional view of the needle set of FIG. 11 takenalong line 13-13.

FIG. 14 is a perspective view of the needle set of FIG. 5 having afiring mechanism;

FIGS. 15-17B show the construction of the inner member of FIG. 7;

FIGS. 18A-18B illustrate a cross-sectional and end-view of a portion ofthe inner member of FIG. 7;

FIGS. 18C-18E illustrate sectional views of an embodiment of a vacuumbed formed in an inner cannula from a trocar blank;

FIGS. 19A-19E illustrate an embodiment of a vacuum bed for use withembodiments of biopsy devices disclosed herein;

FIG. 20A illustrates a vacuum bed formed of a sintered or porousmaterial blank;

FIG. 20B illustrates a vacuum bed formed of a threaded material blank;

FIG. 20C illustrates a vacuum bed formed of a contoured material blankincluding threaded portions;

FIGS. 21A-21C illustrate a vacuum bed formed of a material blankassembly having pre-drilled vacuum passages;

FIGS. 22A and 22B illustrate a vacuum bed formed from a framed meshfilter;

FIGS. 23A-23C illustrate a vacuum bed formed of a plate material;

FIGS. 23D-23H illustrate alternative embodiments of the vacuum bed;

FIGS. 24A-24C illustrate a vacuum bed configured from bendable tabsformed on the cannula;

FIG. 25 is a cross-sectional view of an embodiment of a double-actionbiopsy device;

FIGS. 26A-26E are cross-sectional views of a second embodiment of adouble-action biopsy device;

FIG. 27 is a partial cross-sectional view of another embodiment of adouble-action biopsy device of FIG. 25.

FIG. 28 is a partial cross-sectional view of yet another embodiment of adouble-action biopsy device of FIG. 25.

FIGS. 29A-29C are cross-sectional views of a third embodiment of adouble-action biopsy device;

FIGS. 30A-30D are cross-sectional views of a fourth alternativeembodiment of a double-action biopsy device and;

FIG. 31 illustrates a prespective view with a partially remove housingexposing an actuating platform.

Although the drawings represent embodiments of the present invention,the drawings are not necessarily to scale and certain features may beexaggerated in order to better illustrate and explain the presentinvention. The exemplification set out herein illustrates certainembodiments of the invention, in one, or more forms, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. The invention includes any alterationsand further modifications in the illustrated devices and describedmethods and further applications of the principles of the invention thatwould normally occur to one skilled in the art to which the inventionrelates.

The terms proximal and distal as used herein will be understood todescribe opposite ends of a device or element, and generally will beemployed so that proximal is understood as “toward the heart” and distalis understood to mean “away from the heart” or “away from thepractitioner” and “toward the practitioner,” respectively.

FIGS. 5-10 depict a first embodiment of a needle set 50 for a biopsydevice. Needle set 50 includes an inner member 100 slidably disposedwithin a lumen 58 of an outer member 60. Outer member 60 has a tipmember 61 attached to a center portion 70 and a hub member 80 positionedon the proximal end of outer member 60. Tip member 61 has a working end63 with an opening 63(a) therethrough, an opposite end 64 and a tiplumen 65 defined therebetween. As seen most clearly in FIG. 6, centerportion 70 has a first end 71 hermetically connected to the opposite end64 of the tip member 61 and a second end 73. A center lumen 75 isdefined between first and second ends 71 and 73. The center lumen 75 isin fluid communication with the tip lumen 65. Hub member 80 ispositioned on the second end 73 of the center portion 70. Hub member 80defines a hub lumen 85 that is in fluid communication with the centerlumen 75. The hub lumen 85 is also in fluid communication with a pair ofopenings 86 a, 87 a defined in opposite sides 86, 87 of the hub member80. A vent seal 88 may be disposed within the hub member 80. The secondend 73 of the center portion 70 is attached to hub member 80 at side 86and positioned so that the center lumen 75 is in substantial alignmentwith the hub lumen 85.

A seal member 90 may be positioned within the center lumen 75 and fixedto an interior surface of the center lumen 70. The seal member 90 is anysuitable seal member, such as for example, an O-ring. Seal member 90defines an opening 91, which is in communication with the center lumen75.

Referring now to FIG. 7, inner member 100 includes a cannula 110 and asampling portion 150. Cannula 110 may be slidably disposed within thecenter lumen 75 and through the opening 91 of the seal member 90 asshown in FIG. 5. An inner lumen 115 is defined between distal andproximal ends 101, 102 of corner member 100. Cannula 110 includes anopening 120 and a vent aperture 156 that is positioned adjacent theproximal end 102. Both the opening 120 and vent aperture 156 are formedthrough the wall of the cannula 110 and are in fluid communication withthe inner lumen 115. While opening 120 is shown as a notch, it isunderstood that opening 120 may take the form of other configurationswithout departing from the invention.

Sampling portion 150 is attached to the distal end 101 of cannula 110.Sampling portion 150 includes a sampling cavity 155. Sampling portion150 may also be provided with a tissue piercing tip 153. A cannula sealmember 160 is secured to the outer surface of the cannula 110 proximalto the opening 120. Cannula seal member 160 is configured to movablyseal within the center lumen 75 of FIG. 6.

As shown in FIG. 8, the cannula seal member 160 and the seal member 90cooperate to define a vacuum chamber VC. The opening 120 may be disposedwithin the vacuum chamber VC. The inner and outer members 60, 100 aremovable relative to one another between a retracted position in whichthe tip member 61 covers the sampling cavity 155 and the vacuum chamberVC is expanded, and an extended position. The needle set may be placedin a cocked position as shown in FIG. 8 with the vent aperture 156exposed to vent air A from the inner lumen 115 as the needle set ismoved to the extended position (as shown in FIG. 9A) such that movementof the outer member 60 to the distal position generates vacuum which isdelivered to the inner lumen 115. In the extended position the samplingportion 150 is extended away from the tip member 61 to expose thesampling cavity 155 and the vacuum chamber VC is contracted. The ventaperture 156 is sealed by the vent seal 88 when the needle set iscompletely in the extended position.

As the device is cocked, the inner member 100 is pulled towards theoperator, which exposes the vent aperture 156 beyond the proximal end 87of the hub 80 of the outer cannula 60, as shown in FIG. 8. Referring toFIG. 9B, the inner member 100 is pushed forward to expose the cavity 155to tissue, the vacuum chamber VC is collapsed, as indicated by thecloser proximity between the cannula seal member 160 and the seal member90. Accordingly, air A vented out through the vent aperture 156 alongthe direction of arrow A. The vent aperture 156 is designed to preventpushing air out though the cavity 155. Firing the device causes theouter member 60 to move distally, which expands the vacuum chamber VC.Expanding the vacuum chamber VC creates a vacuum in the inner lumen 115,which is communicated to the cavity 155 as the vent aperture 156 issealed within vent seal 88 disposed within the hub lumen 85. The vacuumgenerated in the extended position serves to bias the tissue toward thesampling cavity 155 and hold the tissue in place while the suspecttissue is severed. Therefore, vacuum is applied to the tissue in cavity155 as the tip member 61 of the outer member 60 moves over the samplingportion 150 of the inner member 100. In contrast, when prior art devicesare used, the outer member tends to push tissue away from the cavity,reducing the size of the sample or requiring multiple attempts tocapture the sample. In the embodiments of the present invention, thevacuum created by the enlargement of the vacuum chamber actuallycaptures and holds the tissue within the cavity 155 resulting in morereliable sampling and larger sample volumes.

The needle set may also include a metering mechanism for selectivelyallowing the exchange of air but not tissue between the cavity 155 andthe inner lumen 115. As shown more clearly in FIG. 10, in one particularembodiment, the metering mechanism includes a filter member 180 fittedwithin the inner lumen 115 or disposed between the inner lumen 115 andthe sampling portion 150. Any suitable material may be employed for thefilter member 180. However, the selected material should, but notnecessarily, have a pore size that allows the exchange of air but is toosmall for body tissue.

An alternative embodiment of the metering mechanism includes the innermember 100′ shown in FIGS. 11-13. The distal tip member 151′ of samplingportion 150′ includes tissue piercing tip 153′ and a solid insert 158.As illustrated by FIGS. 12-13, solid insert 158 has an outer diameter ODthat is less than the inner diameter ID of the inner lumen 115′ so thatair may pass around the insert 158 when the insert is disposed withinthe inner lumen 115′. As shown, the insert 158 is substantially centeredwithin the inner lumen 115′. In alternate embodiments, based on designrequirements, the insert 158 may be shifted to a particular side orportion of the inner lumen 115′ thereby modifying the air flow withinthe inner lumen 115′. The insert 158 and the inner lumen 115′ should be,but not necessarily, dimensioned so that the space between them allowsair to pass but not tissue.

The needle set embodiments herein may be operated via a biopsy device.For example, the needle set can be loaded into a double action biopsydevice or incorporated into a single action biopsy device. FIG. 14illustrates a needle set including an advancing mechanism 159,operatively engaged to the second end 73 of the cylinder 70 and theproximal end 102 of the inner member 100. The advancing mechanism 159 isoperable to move the outer member 60 relative to the inner member 100from the second position to the first position to trap tissue from thebiopsy site in the sampling cavity 155.

The embodiments of the inner member 100 described herein may beconstructed according to the steps depicted in FIGS. 15-18. As shown inFIG. 15, insert 158 may be attached to a connecting element 158 a and ablank 151″. As shown in FIG. 16, insert 158 is positioned within thelumen 115′ of the cannula 110′, with the cannula 110′ friction fitted tothe connecting element 158 a. The connecting element 158 a could be aring or a pair of projections, for example. The sampling cavity 155′ isthen machined through a distal portion 101′ of the cannula 110′ and intothe solid insert 158 to achieve the configuration shown in FIGS.17A-17B. The inner member 100 may be inserted into the cylinder lumen 75of the outer member 60 (as shown in FIG. 8). A tissue piercing tip canbe formed at any point in the process, using any suitable methods, suchas by machining the blank 151″.

FIGS. 18A-18B illustrate an embodiment of an inner cannula 110″ for usewith the needle set described herein. The inner cannula 110″ is formedhaving a thick exterior wall “T” whereby the diameter of the inner lumen115″ is smaller in comparison to thin walled inner cannula 110′. Thedistal end 101″ of the inner cannula 110″ is disposed with a tissuepiercing tip through methods known to those skilled in the art. Asampling cavity 155″ is formed in the distal portion of the innercannula 110″ proximate the tissue piercing tip. The inner cannula 110″is placed in communication with a vacuum source and a vacuum isdelivered through the inner lumen 115″ to the sampling cavity 155″. Thevacuum causes tissue at the biopsy site to be drawn into the samplingcavity 155″ for excision during a biopsy procedure. FIG. 18B generallyillustrates a cross-sectional end-view of the inner cannula 110″ afterthe sampling cavity 155″ has been formed. A portion of the exterior wallof the inner cannula 110″ is removed to expose at least a portion of theinner lumen 115″.

FIGS. 18C-18E illustrate a conventional thin walled inner cannula 110′wherein a vacuum bed 162-9 is formed by first inserting a trocar blank164-1 into the inner lumen 115′ at the distal end of the cannula 110′.The trocar blank 164-1 includes a notch 111 at its proximal end which isformed into a vacuum port when the sampling cavity 161 is formed in theinner cannula 110′. The inner cannula 110′ is placed in communicationwith a vacuum source whereby a vacuum is delivered to the inner lumen115′ to the sampling cavity 161. The vacuum draws tissue into thesampling cavity 161 for excision during a biopsy procedure.

FIGS. 19-24 illustrate alternative embodiments wherein the distalportion 101′ of the inner cannula 110′ is configured as a vacuum bed(162-1 through 162-8). The vacuum beds (162-1 through 162-8) areconfigured to provide a uniform vacuum throughout the sampling cavity161 in order to acquire more uniform and larger core samples.Additionally, the vacuum bed (162-1 through 162-8) operates to providerigidity to the bottom of the inner cannula 110′ which also allows for adeeper sampling cavity 161 to be formed.

FIGS. 19A-19E illustrate a method of configuring a vacuum bed 162-1. Itis appreciated that the method illustrated is merely exemplary as othermethods for configuring the vacuum beds 162-1 through 162-8 arecontemplated. FIG. 19A illustrates a trocar blank 164 used to form thevacuum bed 162-1. The trocar blank 164 is pressed into the distalportion 101′ of the inner cannula 110′. The “A” dimension is sized to bea press-fit into the inner cannula 110′ whereby it is retained byfriction between itself and the lumen of the inner cannula 110′. Inaddition, the “A” dimension has a flat 165 to allow for vacuum travelbeneath and along the sides of the vacuum bed 162-1. The “B” dimensionis sized smaller than the inner diameter of the inner cannula 110′. Oncepressed into the inner cannula 110′, the trocar blank 164 and samplingcavity 161 are ground to form the vacuum bed 162-1 such as by machining.The trocar blank 164 then serves as the trocar tip and the vacuum bed162-1 as illustrated in FIG. 19B. FIGS. 19C and 19D illustrate a vacuumchannel 163 as being formed beneath and at the sides of the vacuum bed162-1. In this fashion, the vacuum that is generated in the innercannula 110′ is uniformly distributed throughout the sampling cavity.FIG. 19E illustrates a top view of the vacuum bed 162-1 after themachining process is completed.

FIG. 20A illustrates a vacuum bed 162-2 formed with a sintered/ porousmaterial. The sintered/porous blank is press-it into the inner cannula110′ and machined as described above to form the vacuum bed 162-2. Thepores in the sintered material allow vacuum to be pulled through thevacuum bed 162-2 and inner cannula 110′, thereby pulling tissue into thesampling cavity 161. FIG. 20B illustrates a vacuum bed 162-3 configuredfrom a threaded blank material and FIG. 20C illustrates a vacuum bed162-4 configured from a contoured and partially threaded blank material.The threads in the blank material provide paths through which vacuum aircan travel to the sampling aperture 161. Each of the vacuum beds (162-3and 162-4) can be constructed in the manner described above or othermethod known to those skilled in the art.

FIGS. 21A-21C illustrate a blank material subassembly used to form avacuum bed 162-5 which contains pre-drilled vacuum passages 173. Atrocar blank 170 and a chamber blank 172 are both machined from stockmaterial. The trocar blank 170 is pressed into the chamber blank 172 asillustrated in FIG. 21B. The subassembled trocar blank 170 and chamberblank 172 are then pressed into the distal end 101′ of the inner cannula110′ where it is retained by friction. Also, the joints between thesubassembled components could be strengthened by laser welding theperimeter of each joint. Final construction consists of grinding thetrocar blank 170 and chamber blank 172 to form a sharpened tip andvacuum bed 162-5, respectively, as illustrated in FIG. 21C. The vacuumis applied through the inner cannula 110′ and travels through thedrilled vacuum passages 173 to create a uniformly distributed vacuum atthe sampling cavity 161.

FIGS. 22A and 22B illustrate a vacuum bed 162-6 formed from a framedmesh filter 176. The framed mesh filter 176 includes substantiallyparallel and rigid elongated frame bars 177 which operate to support themesh filter material 178 between disc-like end portions 179. The framedmesh filter 176 is fixed in the inner cannula 110′ by friction fitbetween the disc-like end portions 179 and the sampling cavity 161 (SeeFIG. 22B. Alternatively, the framed mesh filter 176 may be spot weldedat appropriate points to the inner cannula 110′. The disc-like endportion 179 adjacent the proximal end of the sampling cavity 161preferably includes a vacuum channel 180 which allows for vacuum in theinner cannula 110′ to travel beneath the framed mesh filter 176. Thevacuum channel 180 and framed mesh filter 176 allow for delivery ofvacuum to the sampling cavity 161 while preventing the extrusion oftissue down the inner cannula 110′.

FIGS. 23A through 23E illustrate an alternative method of forming avacuum bed 162-7 through the use of an elongated plate 182 having aplurality of weld points 184 disposed on a bottom surface thereof. Inthis embodiment, the sampling cavity 161 and the sharpened trocar tipwill be ground on the inner cannula 110′ prior to spot welding the plate182 within the sampling cavity 161 to form the vacuum bed 162-7. A rodor plug 186 may be inserted into the inner cannula 110′ to prevent theextrusion of tissue down the inner cannula 110′ (See FIG. 23B). As bestillustrated in FIG. 23C, the vacuum bed 162-7 may include a plurality ofvacuum grooves or holes 188 to aide in pulling tissue into the samplingcavity 161 via the vacuum. FIGS. 23D-23F illustrate an embodiment of avacuum bed 162-7 a formed using the plate 182 a that includes aplurality of weld points 184 a disposed on the bottom surface thereof(See FIG. 23E) and at least one elongated hole or slit 188 a formedalong its longitudinal axis. The elongated slit 188 a permits a vacuumto be distributed substantially the entire length of the elongated plate182 a. In addition to the forming the vacuum beds (162-7, 162-7 a) usingthe respective elongated plates (182, 182 a), stylaric inserts (164-3,164-4) may be disposed in the inner lumen 115′ through the open distalend of the inner cannula 110′ ( See FIGS. 23G-23H). The stylaric inserts(164-3, 164-4) are one piece structures that include a tissue piercingtip and the vacuum bed. The stylaric inserts (164-3, 164-4) areconfigured to be press fitted into the distal end of the inner cannula110′ and may be secured using an adhesive or by other methods known tothose skilled in the art. It is appreciated that the stylaric inserts(164-3, 164-4) illustrated in FIGS. 23G-23H are merely exemplary ofvarious embodiments which would be suitable for use with biopsy devicesdescribed herein and are not intended to be limiting with respect toother configurations.

FIGS. 24A through 24D illustrate an embodiment of a vacuum bed 162-8configured from cut and bend tabs 190 formed in the inner cannula 110′.First the tabs 190 are cut into the inner cannula 110′ and then are bentto form the vacuum bed 162-8. As best illustrated in FIG. 24B, a rod 191may be placed inside the inner cannula 110′ to prevent extrusion oftissue therethrough but allows for vacuum to be delivered to thesampling cavity 161. FIG. 23C illustrates a transverse view of thevacuum bed 162-8 wherein tabs 190 are shown bent inward to vacuum slits192 which allow vacuum to flow through the sampling cavity 161. FIG. 24Dillustrates a top view of the vacuum bed 162-8 providing a detailed viewof the vacuum slits 192.

FIG. 25 illustrates an embodiment of a double action vacuum assistedbiopsy device 200. The biopsy device 200 provides a handpiece 201 thatincludes a cutting element 202 having an outer cannula 204 and an innercannula 206. The outer cannula 204 includes an inner lumen 208, an openproximal end 210, a tissue receiving aperture 212 disposed proximate aclosed distal end 214, and a cylinder seal 216 having a central aperture218 disposed at the open proximal end 210 thereof. Preferably, the outercannula 204 includes a tissue piercing tip 220 that forms the closeddistal end 214. The cylinder seal 216 is fixed to the open proximal end210 such that the central aperture 218 is preferably concentricallypositioned relative to the open proximal end 210 wherein the diameter ofthe central aperture 218 is smaller than the diameter of the openproximal end 210.

The cutting element 202 also includes an inner cannula 206 slidablydisposed within the outer cannula 204. The inner cannula 206 is formedwith an open proximal end 224 and an open distal end 226. The openproximal end 224 is disposed with a push plate 228 having a springcollar 230 formed on a proximal side 232 thereof. The spring collar 230surrounds an opening 234 formed central to push plate 228. The opening234 has a diameter dimensioned such that the open proximal end 224 ofthe inner cannula 206 can be frictionally fixed therein and/or fixedtherein with an adhesive suitable for such purpose.

The open distal end 226 is preferably formed with a razor sharpenedbeveled edge 227 that enhances the tissue cutting ability of the innercannula 206. The inner cannula 206 also includes an inner lumen 236 andat least one vacuum inlet 238 in fluid communication with the innerlumen 236 that is formed through the sidewall of the inner cannula 206.An outer diameter of the inner cannula 206 is dimensioned such that itcan be slidably passed through the central aperture 218 of the cylinderseal 216 while maintaining a fluid seal in relation thereto. The innerlumen 236 also includes a vacuum seal 239 disposed proximate the openproximal end 224. The vacuum seal 239 is selectively engaged andconfigured to assist in maintaining a vacuum within the inner lumen 236in a manner to be described hereinafter.

A vacuum chamber 240 is disposed about a portion of the cutting element202 that includes the open proximal end 210 of the outer cannula 204 andcylinder seal 216, and the at least one vacuum inlet 238 of the innercannula 206. The vacuum chamber 240 includes an open proximal end 242and an open distal end 244. The open proximal end 242 of the vacuumchamber 240 has an inner diameter dimensioned to allow the inner cannula206 to slidably pass therethrough. Preferably, the open proximal endincludes a fluid sealing member 246 such as an O-ring that is configuredto maintained a fluid seal between the inner cannula 206 and the openproximal end 242 of the vacuum chamber 240. The open distal end 244 ofthe vacuum chamber 240 has an inner diameter that is dimensioned toallow the outer cannula 204 to slidably pass therethrough. Preferably, afluid sealing member 248 is disposed at the open distal end 244 of thevacuum chamber 240 that is configured to maintain a fluid seal betweenthe open distal end 244 of the vacuum chamber 240 and the outer cannula204.

The vacuum chamber 240 includes an internal spring housing 250 formedabout the open proximal end 242 and extending axially toward the opendistal end 244. The internal spring housing 250 is preferably formedconcentric to the open proximal end 242 and is disposed with a firstfiring spring 252. The first firing spring 252 includes a proximal end254, a distal end 256, and an inner diameter that is dimensioned toallow the inner cannula 206 to pass freely therethrough. The firstfiring spring 252 is disposed within the internal spring housing 250such that the proximal end 254 contacts the open proximal end 242 of thevacuum chamber 240 and the distal end 256 contacts the cylinder seal216.

As best illustrated in FIG. 27, the vacuum chamber 240 may also includea one way flow valve 257. The one way flow valve 257 is in communicationwith a fluid reservoir 259 filled with an absorbent material 261. Thefluid reservoir 259 is configured to receive and retain a volume offluid from the vacuum chamber 240 that may accumulate therein during thebiopsy procedure. The absorbent material 261 cooperates with the fluidreservoir 259 to receive and retain the volume of fluid.

Referring again to FIG. 26, a tissue stop 258 is provided and configuredto be slidably received within the inner lumen 236 of the inner cannula206 through the vacuum seal 239 disposed at the open proximal end 224thereof. In one embodiment, the tissue stop 258 extends the entirelength of the inner cannula 206 from the open proximal end 224 to theopen distal end 226 thereof. The tissue stop 258 includes a knob portion260 disposed at a proximal end 262 thereof which may be used foradjusting the position of the tissue stop 258 within the inner cannula206.

A second firing spring 264 is disposed between the knob portion 260 ofthe tissue stop 258 and the push plate 228 of the inner cannula 206. Aproximal end 266 of the second firing spring 264 engages the knobportion 260 and a distal end 268 engages the push plate 228 about thespring collar 230. Preferably, the second firing spring 264 is fixed toat least one of the knob portion 260 or push plate 228 to enhance theoverall stability of the biopsy device 200.

A trigger mechanism 270 is provided and configured to cause the firstfiring spring 252 to advance the outer cannula 204 distally outwardlysuch that the closed proximal end 220 of the outer cannula 204penetrates into the biopsy site. Shortly therafter, the second firingspring 264 causes the inner cannula 206 to move distally outwardlywhereby a tissue sample drawn into the tissue receiving aperture 212 issevered and retained in the inner lumen 236 of the inner cannula 206.

Referring now to FIGS. 25 and 26A through 26E, before performing abiopsy procedure with the biopsy device 200, the device 200 is cocked byholding the handpiece and compressing the first and second firingsprings (252, 264) until they are cocked (See FIGS. 25-26B). Thereafter,the biopsy device 200 is positioned for penetration into the biopsysite.

Next at FIG. 26C, the trigger mechanism 270 is actuated causing therelease of the first 252 firing spring. When the outer cannula 204 isadvance distally outwardly by the first firing spring 252 into thebiopsy site, the cylinder seal 216 within the vacuum chamber 240 isadvanced forward such that it passes the at least one vacuum inlet 238formed in the wall of the inner cannula 206. Once the cylinder seal 216passes the at least one vacuum inlet 238, a vacuum is generated in thevacuum chamber 240 that is delivered to the tissue receiving aperture212 via the inner lumen 236 of the inner cannula 206. The vacuum alsocauses the one-way valve 257 (See FIG. 27) to close such that the vacuumis maintained within vacuum chamber 240. Further, the vacuum seal 239 iscaused to engaged the tissue stop 258 such that the vacuum can bemaintained at the inner lumen 236. The vacuum generated by the vacuumchamber 240 operates to cause tissue at the biopsy site to be drawn intothe tissue receiving aperture 212 thus improving the chances that asufficent tissue sample will be obtained.

Referring now to FIG. 26D, a short predetermined period after the outercannula 204 has been fired, the inner cannula 206 is advanced distallyoutwardly by the second firing spring 264. The sharpened beveled edge227 of the inner cannula 206 severs the tissue drawn into the tissuereceiving aperture 212 and the tissue sample is held within the innerlumen 236 of the inner cannula 206 proximate the open distal end 226thereof by the tissue stop 258. To further enhance to cutting ability ofthe inner cannula 206, it may be configured to rotate as it is advanceddistally outwardly creating a slicing and shearing action for severingthe tissue.

Referring now to FIG. 26E, after removing the biopsy device 200 from thebiopsy site, the tissue sample can be retrieved from the tissuereceiving aperture 212 of the outer cannula 204 by retracting the innercannula 206 whereby the tissue sample is exposed for removal. The biopsydevice 200 is thereafter cocked causing the vacuum seal 239 and theone-way valve 257 to open whereby the vacuum is released and any fluidbuilt up within the vacuum chamber 240 is allowed to flow into the fluidreservoir 259 (See FIG. 27).

As best illustrated in FIG. 28, an embodiment of the biopsy device 200may be configured to cooperate with the fluid reservoir 259 beingdisposed in-line between the vacuum chamber 240 and a vacuum source 280.The vacuum source 280 may be any fluid source capable of providing avacuum to the biopsy device 200, for example, a vacuum generatingmachine or a CO₂ cartridge. Preferably, the vacuum source 280communicates with the vacuum chamber 240 through tubing 282 and a vacuumport 284. In this embodiment, the open proximal end 210 of the outercannula 206 is disposed with a flange 286 that seats over the internalspring housing 250 when the biopsy device 200 is cocked such that thefirst firing spring 252 is in mechanical communication therewith.Preferably, the actuation of the trigger mechanism 270 causes the firstfiring spring 252 to advance the outer cannula 204 distally outwardlyand the vacuum source 280 to power on such that a vacuum is generated inthe vacuum chamber 240. The generated vacuum is delivered to the innercannula 206 via the at least one vacuum inlet 238. The vacuum causestissue at the biopsy site to be drawn into the tissue receiving aperture212 of the outer cannula 204. Thereafter, the second firing spring 264causes the inner cannula 206 to be advanced distally outwardly wherebythe tissue within the tissue receiving aperture 212 is severed. Fluidentering the vacuum chamber 240 is drawn through the vacuum port 284 andtubing 282 into the fluid reservoir 259. After the tissue sample hasbeen obtained the vacuum source 280 is turned off and the tissue samplecan be removed from the biopsy device 200 in the manner described above.

Another embodiment 200′ of the biopsy device is configured to allow theinner cannula 206 to be fired prior to firing the outer cannula 204. Inthe embodiment FIGS. 29A through 29C, the handpiece 300 includes thevacuum port 302 in communication with a vacuum channel 304 thatcommunicates with vacuum chamber 306. The vacuum port 302 alsocommunicates with a fluid reservoir 308 and vacuum source 310 throughtubing 312. The cutting element 314 includes an inner cannula 316 and anouter cannula 318 wherein a portion of the cutting element 314 is housedby the handpiece 300. The outer cannula 318 includes open proximal 320and distal 322 ends wherein the open distal end 322 preferably includesa razor sharpened edge 324 and the open proximal end 320 includes asecond spring flange 326 formed integral thereto. The inner lumen 328 ofthe outer cannula 318 includes a vent seal 330 disposed proximate theopen proximal end 320 thereof.

The inner cannula 316 includes a closed proximal end 332 and a closeddistal end 334 wherein the closed distal end 334 is disposed with atissue receiving aperture 336 proximate thereto (See FIG. 29B). Theclosed distal end 334 is provided as a working end formed with a sharptip 338 for penetrating through tissue into the biopsy site. The innercannula 316 includes at least one vacuum inlet 340 formed proximate theclosed proximal end 332 and at least one vent aperture 342 formedbetween its proximal 332 and distal 334 ends. The closed proximal end332 includes a first spring flange 344 formed integral thereto.Preferably, the inner lumen 346 of the inner cannula 316 is disposedwith a tissue stop 348 proximate a proximal end 350 of the tissuereceiving aperture 336. The inner cannula 316 is configured with anouter diameter that allows it to be slidably received into the outercannula 318 through the vent seal 330 while maintaining a fluid sealtherewith. The inner cannula 316 passes through the vacuum chamber 306along a longitudinal axis of the handpiece 300. The sidewalls of thevacuum chamber 306 include seal members 352, for example, O-rings at thelocation where the inner cannula 316 passes along the longitudinal axis.The inner cannula 316 has an outer diameter dimensioned to slidably passthrough the seal members 352 while maintaining a fluid sealtherebetween.

Referring now to FIG. 29B, the first firing spring 354 is disposed aboutthe inner cannula 316 between the first spring flange 344 and theproximal end 356 of the handpiece 300. The first firing spring 354operates to advance the inner cannula 316 distally outwardly into thebiopsy site after the trigger mechanism 358 has been actuated. Thesecond firing spring 360 is disposed about the inner cannula 316 betweenthe second spring flange 326 and the distal sidewall 362 of the vacuumchamber 306. The second firing spring 360 causes the outer cannula 318to be advanced distally outwardly after the inner cannula 316 has beenfired (See FIG. 29C).

Upon actuating the trigger mechanism 358, the first firing spring 354advances the inner cannula 316 distally outwardly such that the workingend penetrates into the biopsy site and causes the at least one ventaperture 342 to become closed by the vent seal 330. Additionally, the atleast one vacuum inlet 340 is advanced to a position within the vacuumchamber 306. The vacuum source 310 is powered on and a vacuum isgenerated in the vacuum chamber 306 which is delivered to the innercannula 316 through the vacuum inlet 340. The vacuum source 310 may beturned on manually or automatically in response to the inner cannula 316being fired. The vacuum causes tissue to be drawn into the tissuereceiving aperture 336 of the inner cannula 316 and fluid from thebiopsy site to be drawn into the fluid reservoir 308.

After the inner cannula 316 has been fired, the outer cannula 318 isadvanced distally outwardly by the second firing spring 360 and thetissue drawn into the tissue receiving aperture 336 of the inner cannula316 is severed and held in the inner lumen 346 of the inner cannula 316proximate the tissue receiving aperture 336 by the tissue stop 348. Theouter cannula 318 may be configured to rotate while being advanceddistally outwardly thereby producing a slicing and shearing action forsevering the tissue at the biopsy site. After the biopsy device 200′ isremoved, the tissue sample is removed by turning off the vacuum source310 and retracting the outer cannula 318 such that the tissue sample isexposed.

FIGS. 30A-30D illustrate another embodiment 200″ of a biopsy devicehaving a cutting element mounted to a housing. With reference to FIG.30A, the biopsy device 200″ includes a housing 400 having a cuttingelement 402. The cutting element 402 includes an inner cannula 404 andan outer cannula 406. As best illustrated in FIG. 30B, the inner cannula404 has a sharpened tip 405 formed at its distal end 414. A tissuereceiving aperture 412 is formed proximal to the sharpened tip 405 andis configured for receiving tissue to be excised in the cutting processto be described below.

Still referring to FIG. 30B, the inner cannula 404 is slidably disposedwithin the outer cannula 406. Preferably, the outer cannula 406 includesa razor sharpened beveled edge 416 formed at its distal end 418 forenhancing its ability to cut tissue.

A vacuum chamber 408 is disposed proximate the proximal end 420 of theinner cannula 404. The vacuum chamber 408 operates to cause a vacuum tobe generated in the inner cannula 404 whereby tissue to be excised isdrawn into the tissue receiving aperture 412 such that the probabilityof obtaining an adequate sample is increased.

As illustrated in FIG. 30C, a trigger mechanism 410 is provided forcausing the cutting element 402 to excise a tissue sample as will bedescribed below. The trigger mechanism 410 includes a first trigger arm422 which causes the firing of inner cannula 404 when actuated and asecond trigger arm 424 which causes the firing of the vacuum chamber 408and, thereafter, the firing of the outer cannula 406 during the biopsyprocedure. A biopsy procedure using the present embodiment will bedescribed with reference to FIGS. 30A-30D. FIG. 30A illustrates thebiopsy device 200″ wherein the inner cannula 404, outer cannula 406 andvacuum chamber 408 are retained in a cocked position by the first 422and second 424 trigger arms of the trigger mechanism 410.

Referring to FIG. 30B, the trigger mechanism 410 is actuated to causethe first trigger arm 422 to allow the firing of the proximal end 414 ofthe inner cannula 404 into the biopsy site. Next, as best illustrated inFIG. 30C, the trigger mechanism 410 is actuated a second time to causethe second trigger arm 424 to allow the vacuum chamber 408 to be fired.Firing of the vacuum chamber 408 causes a vacuum to be generated in theinner cannula 404 whereby tissue at the biopsy site is drawn into thetissue receiving aperture 412. In addition to causing the vacuum to begenerated in the inner cannula 404, as illustrated in FIG. 30D, thefiring of the vacuum chamber 408 causes the outer cannula 406 to firedwhereby the tissue drawn into the tissue receiving aperture 412 issevered. The tissue sample may be removed from the inner cannula 404 bypulling the outer cannula 406 back to the cocked position to expose thetissue sample.

In one embodiment 500, the biopsy device is moved from an uncockedposition to a cocked position by squeezing the handle 510 of the biopsydevice three consecutive times to sequentially return the vacuum hub502, the inner cannula hub 504, and the outer cannula hub 506 to thecocked position via an actuating platform 508. The actuating platform508 is spring loaded and slidably reciprocates between uncocked andcocked positions within the biopsy device. Squeezing the handle 510 ofthe biopsy device a first time causes the vacuum hub 502 to move from auncocked position to a cocked position. A second squeeze causes theinner cannula hub 504 to move from a uncocked position to a cockedposition and a third squeeze causes the outer cannula hub 506 to movefrom an uncocked position to a cocked position. The handle 510 of thebiopsy device must be squeezed three times before any one core can beretrieved from the biopsy device after it has been severed.

The assemblies of this invention can be provided in any suitable shapeand size and can be manufactured using any suitable materials. In oneparticular embodiment, the needle set is composed of surgical gradestainless steel. Other embodiments of the invention will be apparent tothose skilled in the art from consideration of the specification andpractice of the invention disclosed herein. It is intended that thespecification, drawings and examples be considered as exemplary only,with the true scope and spirit of the invention being indicated by thefollowing claims. It should be understood that the embodiments shown anddescribed and all changes and modifications that come within the spiritof the invention are desired to be protected.

1. A biopsy device, comprising: a cutting element mounted to ahandpiece, said cutting element comprising: an outer cannula having openproximal end and a tissue receiving aperture at a distal end thereof; aninner cannula being slidably mounted within said outer cannula andhaving an open distal end; a vacuum chamber disposed about at least aportion of said cutting element; wherein said outer cannula isselectively advanced distally outwardly thereby causing a vacuum to begenerated in said vacuum chamber and delivered to said inner cannula,said vacuum causing tissue to be drawn into said tissue receivingaperture; and wherein said inner cannula is operative to be advanceddistally outwardly after said outer cannula such that the tissue drawninto said tissue receiving aperture is severed by said inner cannula. 2.The biopsy device of claim 1 wherein said inner cannula furthercomprises a tissue stop disposed within an inner lumen thereof.
 3. Thebiopsy device of claim 1 wherein said outer cannula further comprises acylinder seal disposed proximate a proximal end thereof.
 4. The biopsydevice of claim 1 wherein a first firing spring causes said outercannula to advance distally outwardly.
 5. The biopsy device of claim 4wherein a second firing spring causes said inner cannula to advanceafter said outer cannula is advanced.
 6. The biopsy device of claim 1wherein said inner cannula further includes at least one vacuum inlet.7. The biopsy device of claim 1 wherein said vacuum chamber furthercomprises a one way flow valve.
 8. The biopsy device of claim 7 whereinsaid one way valve communicates with a fluid reservoir.
 9. The biopsydevice of claim 8 wherein said fluid reservoir contains an absorbentmaterial.
 10. The biopsy device of claim 1 wherein said open distal endof said inner cannula includes at least one sharpened beveled edge. 11.The biopsy device of claim 1 further including a trigger mechanism thatis disposed at a proximal end of said tissue stop; said triggermechanism selectively advancing said outer cannula.
 12. The biopsydevice of claim 1 wherein said inner cannula is configured to rotatewhile being advanced distally outwardly.
 13. A biopsy device comprising:a cutting element mounted to a handpiece, said cutting elementcomprising: an outer cannula having a cutting tip at a distal endthereof; an inner cannula having an inner lumen and a tissue receivingaperture at a distal end thereof and being slidably mounted within saidouter cannula; a vacuum chamber formed in said handpiece; said vacuumchamber being detachably connected to a vacuum source; a triggeroperative to cause said inner cannula to be advanced distally outwardlyand to cause a vacuum generated in said vacuum chamber to provide avacuum to said inner cannula, said vacuum causing tissue to be drawninto said tissue receiving aperture; and wherein said outer cannula isoperative to be advanced distally outwardly after said inner cannulasuch that the tissue drawn into said tissue receiving aperture issevered.
 14. The biopsy device of claim 13 further comprising a fluidreservoir in communication with said vacuum chamber.
 15. The biopsydevice of claim 13 wherein said inner cannula further comprises a ventaperture and a vacuum aperture in communication with said inner lumen.16. The biopsy device of claim 13 wherein said outer cannula includes asharpened beveled edge at said distal end.
 17. The biopsy device ofclaim 13 wherein said outer lumen further comprises a vent seal disposedwithin an inner lumen thereof.
 18. The biopsy device of claim 17 whereinsaid vent seal is proximate said vent aperture of said inner cannula.19. The biopsy device of claim 13 wherein said inner cannula passesthrough openings formed in said vacuum chamber along a longitudinal axisof said handpiece.
 20. The biopsy device of claim 19 wherein openings insaid vacuum chamber are disposed with fluid seals that allow said innercannula to slidably pass therethrough.
 21. The biopsy device of claim 13further comprising a tissue stop disposed within said inner cannula. 22.The biopsy device of claim 13 wherein said outer cannula is configuredto rotate while being advanced distally outwardly.
 23. The biopsy deviceof claim 13 further comprising a vacuum bed formed in a distal portionof said inner cannula.
 24. The biopsy device of claim 23 wherein saidvacuum bed is formed of a sintered material.
 25. The biopsy device ofclaim 23 wherein said vacuum bed is formed from a threaded blankmaterial.
 26. The biopsy device of claim 23 wherein said vacuum bed isformed from a contoured and partially threaded blank material.
 27. Thebiopsy device of claim 23 wherein said vacuum bed is formed of asubassembly of a trocar blank and a chamber blank.
 28. The biopsy deviceof claim 23 wherein said vacuum bed is formed from a framed mesh filter.29. The biopsy device of claim 23 wherein said vacuum bed is formed of aplate material disposed in said tissue receiving aperture.
 30. Thebiopsy device of claim 29 wherein said plate material includes aplurality of vacuum grooves or holes.
 31. The biopsy device of claim 23wherein said vacuum bed is configured from cut and bend tabs formed in adistal portion of said inner cannula.
 32. The biopsy device of claim 23in communication with a vacuum generating device.
 33. The biopsy deviceof claim 32 wherein said vacuum generating device is a CO₂ cartridge.34. A biopsy device comprising: a cutting element mounted to ahandpiece, said cutting element comprising: an outer cannula; an innercannula having an inner lumen and a tissue receiving aperture at adistal end thereof and being slidably mounted within said outer cannula;a vacuum chamber disposed in said handpiece and affixed to a proximalend of said inner cannula; and a trigger mechanism operative to causesaid inner cannula to be advanced distally outwardly in response to afirst actuation and to cause said vacuum chamber to be advanced distallyoutwardly in response to a second actuation, said second actuationcausing a vacuum to be generated in said inner cannula and causing saidouter cannula to be advanced distally outwardly whereby tissue drawninto said tissue receiving aperture by said vacuum is severed.
 35. Thebiopsy device of claim 34 wherein said trigger mechanism is comprised ofa first and a second trigger arm.
 36. The biopsy device of claim 34wherein said outer cannula includes at least one sharpened beveled edge.37. The biopsy device of claim 34 wherein said inner cannula includes asharpened tip.
 38. The biopsy device of claim 34 further comprising avacuum bed formed in a distal portion of said inner cannula.
 39. Thebiopsy device of claim 34 wherein said inner cannula is a thick-walledinner cannula.
 40. The biopsy device of claim 38 wherein said vacuum bedis formed from a sintered material.
 41. The biopsy device of claim 38wherein said vacuum bed is formed from a threaded blank material. 42.The biopsy device of claim 38 wherein said vacuum bed is formed from acontoured and partially threaded blank material.
 43. The biopsy deviceof claim 38 wherein said vacuum bed is formed of a subassembly of atrocar blank and a chamber blank.
 44. The biopsy device of claim 38wherein said vacuum bed is formed from a framed mesh filter.
 45. Thebiopsy device of claim 38 wherein said vacuum bed is formed from atrocar blank having a notch formed on a proximal end thereof.
 46. Thebiopsy device of claim 45 wherein said notch is converted to a vacuumport when said tissue receiving aperture is formed in the inner cannula.47. The biopsy device of claim 38 wherein said vacuum bed is formed of aplate material disposed in said tissue receiving aperture.
 48. Thebiopsy device of claim 47 wherein said plate material includes aplurality of vacuum grooves or holes.
 49. The biopsy device of claim 47wherein said plate material includes at least one elongated slit. 50.The biopsy device of claim 38 wherein said vacuum bed is configured fromcut and bend tabs formed in a distal portion of said inner cannula. 51.The biopsy device of claim 38 in communication with a vacuum generatingdevice.
 52. The biopsy device of claim 51 wherein said vacuum generatingdevice is a CO₂ cartridge.
 53. The biopsy device of claim 38 whereinsaid vacuum bed is formed by disposing a stylaric insert into the distalend of said inner cannula.